1. Field of the Invention
The present invention relates to improvements of an apparatus for manufacturing microcrystal particles and a method for manufacturing the microcrystal particles, and in particular relates to the apparatus suitable to manufacture the microcrystal particles having diameters less than 20 nm and the manufacturing method of the same.
2. Description of the Related Art
Recently, attention is given to microcrystal particles because a cluster of microcrystal particles obtained by extremely micronizing crystalline particles made from a original material shows different properties from the properties of the original material itself due to a great difference with a total surface area per unit weight, comparing the cluster of microcrystal particles with the original material. The microcrystal particles generally designates crystalline particles having diameters 1 to 20 nm, and the cluster of the microcrystal particles is considered to be in a new state where the cluster of the microcrystal particles behaves in different ways from that of the original material, for example, due to the volume effect or the surface area effect, which is never observed in the original material.
Advent of new electronic devices having properties essentially different from those of the prior art is expected by employing such microcrystal particles made from, for instance, semiconducting materials, metallic materials and insulating materials in the electronic devices. For example, the microcrystal particles made from magnetic materials are expected to be employed for magnetic tapes having high coersive force (Hc), and magnetic heads having high permeability (.mu.). On the other hand, microcrystal particles made from optical materials (dielectric material) are expected to create nonlinear optical devices.
In particular, in the case of micronizing semiconductor material, for example, silicon into the microcrystal particles having diameters less than 20 nm, a luminescent phenomenon and a tunnel effect are observed due to the wave property of electrons caused by the quantum effect. Thus, advent of new devices is expected by making use of the luminescent phenomenon and the tunnel effect of the microcrystal particles for the electronic devices.
Taking an example of an electronic device employing the microcrystal particles made from silicon, it is confirmed that the luminescence phenomenon is observed to occur in the electronic device by a photo-luminescent effect when the silicon is micronized into the microcrystal particles having diameters less than 5 nm, though silicon has been considered to be unavailable as a light-emitting diode in the prior art.
Further, if the luminescent phenomenon occur by current injection, the microcrystal particles is expected to be applied for realizing the high speed connection means between plural LSIs which are congenial with silicon material, and flat displays.
On the other hand, in the prior art, there is proposed such methods as a evaporation/cohesion method, catalisys method, a plasma method and a laser method for producing microcrystal particles applicable to, for instance, the emitting diode, however, attention is in particular given to the laser method.
Next, the description is given to the microcrystal particles producing apparatus in the prior art referring to FIG. 1.
FIG. 1 is a diagrammatic sectional view of an apparatus for producing microcrystal particles in the prior art.
As shown in FIG. 1, 2 designates a reactor, 4 a charging line connected to the reactor 2 for providing raw material gas, for instance, silane gas (SiH.sub.4) into the reactor 2, 6 a laser oscillator for emitting a laser beam L, for instance, a CO.sub.2 gas laser beam, 8 a condenser lens for focusing the laser beam L from the laser oscillator 6 in the low material gas, 20 an exhaust pipe line for occasionally exhausting atmosphere gas from the reactor 2 to control the gas pressure therein, which is measured with a pressure gage P. The gas pressure in the reactor is held at a predetermined pressure, for example, 30 Torr.
When the laser beam L having a high energy density is irradiated on the silane gas, a dielectric gas breakdown accompanying plasma phenomenon together with strong luminescence and keen sound is generated by almost completely absorbing the energy of the laser beam L, so that Si microcrystal particles are produced by the dielectric gas breakdown.
However, in the case of producing the Si-microcrystal particles by using the above apparatus, it was only able to obtain the Si-microcrystal particles having diameters about 0.05.about.1 .mu.m, and the electric devices produced by using such Si-microcrystal particles as having comparatively lager diameters never showed strong luminescent phenomenon, tunnel effect and ultraspeed phenomenon.